When people know more about others, they think others know more about them. Across nine laboratory experiments, when participants learn more about a stranger, they felt as if the stranger also knew them better. As a result, participants were more honest around known strangers. We tested this further with a field experiment in new york city in which we provided residents with mundane information about neighborhood police officers. We found that the intervention shifted residence perceptions of officers knowledge of legal activity and may even have reduced crime.